Are you using WiFi? If so disable WiFi power management https://unix.stackexchange.com/questions/269661/how-to-turn-off-wireless-power-management-permanently

I found a similar issue here: https://bbs.archlinux.org/viewtopic.php?id=281910

It looks like disabling 802.11ax fixed the issue.

A post on StackExchange shows a user that was having this issue in Windows as well (and solved it by disabling 802.11ax) and was looking for instructions on disabling it in Linux.

So it sounds like some Intel wifi cards have issues with 802.11ax, disabling it makes the card use 802.11ac which seems to work just fine.

Are you using the package manager? If yes, try refreshing your mirrors.

If this happens to Windows as well, it’s unlikely that it’s Fedora’s fault. Something else is at play.

Here’s my testing recommendations

Testing methodology

To get consistant results, use a consistent method of test. If you’re downloading a large file, always test by downloading that same file from that same source. If you’re using a speed test service, use the same speed test service with the same server. If you’re using a tool like iperf3, always use the same tool against the same iperf server.

Potential issues

Networks can fail from hardware issues, software issues and infrastructure issues. Since you don’t control 99.9% of the infrastructure if the internet is involved, lets leave that for the last option.

Hardware Issues

The hardware involved you control are mostly your NIC, and your Remote Connection. For wired ethernet at home, this is likely a physical ethernet port on your computer on one end, and another physical ethernet port on a switch/router/ap provided by your ISP.

Testing Wired Hardware Issues

• Using the same switch and cable, run a speed test on another computer. If the issue persists, the problem is not with your computer, if it resolves, its related to your computer.
• Using the same computer and cable, run a speed test on another switch. If the issue persists, its not the switch or cable, its your computer, if it resolves, its not your computer.
• Using the same computer and switch, use a different cable. If the issue persists, it’s not the cable and its either your computer or switch, if it resolves, its the cable.

With these three you can figure out what device is causing the problem.

Testing Wireless Hardware Issues

The hardware involved is the wireless NIC in your computer, the environment your wifi signal is in, and the wifi AP. The steps are much the same as testing for a wired issue

• Using the same AP and physical location, run a speed test on another computer. If the issue persists, the problem is with the AP or location, if it doesn’t it may be your computer
• Using the same computer and physical location, run a speed test on another AP. if the issue persists, the problem is with your computer or location, if it resolves, it may be the AP
• Using the same computer and AP, run a speed test in another physical location. If the issue persists, the problem is with the computer or AP, if it resolves it may be the environment

Software Issues

The issue could be software related. Something like the drivers running on your laptop or connection point.

Testing Computer Drivers

You’ve already done this for your computer by dual booting. This proves the issue is not driver related, since the problem persists with two different sets of drivers.

Testing Connection Point Drivers

• You have less control over the drivers on your switch/router/ap. If the hardware tests resolve when using a different AP, then you can attempt a firmware upgrade/downgrade before replacing the physical device. This isn’t usually worth the hassle since ISPs are quick to replace them with a service call.

Testing Computer Configuration

Your network settings could be misconfigured.

• If you are using DHCP, turn it off, and enforce a speed negotiation, IP address, subnet mask, and DNS server and try again. If the issue persists, then it’s likely not related to your configuration. If it resolves it probably is.
• If you are using a static configuration, turn it off and use DHCP. If the issue persists, it’s likely not related to your configuration, if it resolves, it probably is

Infrastructure Issues

If your home network is more sophisticated then an ISP provded router/switch/ap combo connected to everything over wifi and ethernet, theres more devices to troubleshoot. But if you have something like this, you probably already know what you’re doing a little bit and wouldn’t be making this post. But who knows! Re-run the process isolating each device and replacing it with something known good to identify whats causing the problem.

As for the internet, it’s not a stable and safe place. Speeds vary drastically day to day. Internet weather happens and partial outages occur regularly. Don’t forget that the service your using to speed test could be the issue itself. It’s another component to isolate and test.

Process

Use the above steps to identify what device is causing the problem, and if its a hardware or software issue. Hardware issues are mostly resolved by replacing devices, while software issues are resolved with software updates and configuration changes.

Good luck and god speed!

I gave of MacOS when an OS update included a firmware rollback which disabled gigabit Ethernet on the NIC. So the Fedora install.may have updated the firmware or changed a firmware setting.

Aside from this issue, Fedora has been great! Everything works as expected, UI is fast and snappy, and somehow the file system seems to be a bit faster too (read/write speeds are more consistent)

how is the signal strength? did you open up the laptop to swap the ssd or something?

what network card are you using? are you downloading from the same websites that you get faster download speeds from on windows?